Resonant honing



J. E. KLINE RESONANT HONING June 7, 1960 4 Sheets-Sheet 1 Filed Jan. 31,1957 INVENTOR.

12% Z //Zze. BY

firnnwsys.

June 7, 1960 J. E. KLINE 2,939,250

RESONANT HONING Filed Jan. 31, 1957 4 Sheets-Sheet 2 I sis INVENTOR.

4 Mp2 I YZM I June 7, 1960 Filed Jan. 31, 1957 J. E. KLINE RESONANTHONING 4 Sheets-Sheet 3 INVENTOR.

, piece surface.

RESONANT HONING John E. Kline, Grosse Pointe Farms, Micln, assignor toMicromatic Hone Corporation, Detroit, Mich., a corporation of MichiganFiled Jan. 31, 1957, Ser. No. 637,486

7 Claims. (Cl. 51-34) This invention relates to honing devices, andparticularly to a honing device employing a high order of vibration forproducing rapid and continuous honing.

The invention pertains to a new and useful application of wave-energy tosupplement the present honing, superfinishing, polishing and similaroperations performed by abrasives of the rigidly bonded types, incontast with those employing loose grit or abrasive slurries. It hasheretofore been the practice in the honing art to cause the bondedabrasive honing stones to bear against the workpiece surface with aforce sulficient to obtain penctration of the abrasive grain into thework surface while relatively rotating and reciprocating the workpieceand the abrasive stones. So long as such penetration and motions obtain,the abrasive particles may shear the work material and thereby hone thework surface. But, abrasive grains, like all other cutting tools, becomedull due to attritional or solid solubility wear, and hence, theiroutward surface areas become too large or too smooth to permit continuedpenetration. It is then termed in a glazed condition. Thus, thecondition of the workcontacting face of the abrasive stone is animportant function of its ability to perform efliciently as an abrasiverather than as an excellent bearing surface which it becomes whenglazed.

The grains employed tomake hone' abrasive stones are brittle and usuallyof silicon carbide or fused alumina with the bonding material avitrescent substance. latter may have many physical properties similarto those of the grain, but are of very much lower hardness predicatedupon their relative ability to indent or scratch other materials. Whenthis indentation exists and the grain is subjected to .sufiicienttangential force, it must either scratch the surface or it or its bondmust fracture and thereby be re-sharpened.

A high ratio of grit to bond, in the order of 90% to 10% or less, isemployed in the formulation of hone abrasive stones to make themcompetent of self-dressing under reasonably normal conditions ofoperation. As additional assurance of this, abrasive bonds of softgrades are deliberately chosen which are overly self-dressing to avoidthe imponderable problem of periodically redressing them, withthe resultof ineflicient abrasive life. The ideal rate of self-dressing of theabrasive is that which enables the greatest amount of material displacedfrom the workpiece per unit abrasive expended per unit time.Disintegration is the best form of self-dressing as it produces asharpening effect on the abrasive stone face by fracture of dulledabrasive grains to thereby create new cutting edges, or by fracture ofthe bond to dislodge the grains and expose new grains to the work- Theuse of a high order of vibratory motion, in the form of wave-energy,when applied at a'proper frequency and amplitude, not only prevents theglazing of the rigidly bonded honing stones but reduces the amount ofpower and pressure required to perform the honing operation. In thepresent invention, the mo- I tion induced by the wave energy issupplementary to the The.

atent principal machining forces which are derived from the rotary andtranslatory motions presently employed. The highly cyclical wave motionproduces an entirely diflerent action than the similar but slowersuperimposed motion disclosed in the patent to Peden, No. 2,350,527,issued June 6, 1944, and assigned to the assignee of the presentinvention. It is axiomatic that currently-used abrasive honing stonesare of harder grades for operation upon soft or low tensile strengthmaterials than those normally used for hard or high tensile strengthmaterials. The latter is contrary to the best interest of abrasive life,but is necessary to enable a self-dressing action on the face of thehoning stone suflicient to sustain cutting on hard materials.

The use of wave energy during the honing operation does not directlyproduce the cutting action on the workpiece but functions to conditionthe working surface of the. abrasive stones to any desired state ofeffectiveness. In this process, the workpiece surface being honedliterally performs as the tool for conditioning the abrasive stones. Atresonance a system absorbs and dissipates energy at a maximum rate. Thelocale of such dissipation occurs principally at the point of theweakest couple which is at the abrasive-to-workpiece points of contact.Numerous tests of the principles of this invention have shown that honeabrasive stones with the hardest bonding materials are readily dressedin use by the influence of wave energy employed as herein described. Ifthe workpiece is soft or of low tensile strength, intermittent use ofsaid energy during the operation may suffice. Alternatively, acontinuous application of wave energy may be necessary throughout theheavy stock removal phase of the honing operation in the case of hard"or high tensile strength materials. V

It is an object of this invention to make possible the use ofhard-grain, long-life honing stones. i

It is a further object of this invention to induce vibration at theinterface of the work surface and the abrasive honing stones tosupplement andthereby reduce the pressure required therebetween foreffecting ready penetration of said surface by the abrasive grain of thestones.

Another object of this invention is to induce in a workpiece surface andan abrading tool carrying rigidly bonded abrasive stones in contacttherewith,-an energy wave approximating the frequency of resonance ofeither said workpiece or said toolora harmonic thereof and thus create ahigh-frequency, high-velocity impact therebetween to cause percussiveattribution of the surface of said abrasive stones which sharpens andconditions the working faces thereof for maintaining continuous. andeflicient abrasion of the workpiece surface; Still another object of theinvention is to provide means for employing wave energy to improve theefiiciency and range of application of honing operations in whichrigidly bonded abrasive stones are used as the cutting medium. Otherobjects and features of novelty of the invention will be specificallypointed out or will become apparent when referring, for a betterunderstanding of the invention, to the following description taken inconjunction with the accompanying drawings, in which: a

Figure 1 is a diagrammatic view, with parts in section and parts inelevation, illustrating one embodiment of this invention in which thetool is vibrated; 1

Fig. 2 is an enlarged broken sectional view of a portion of thestructure illustrated in Fig. 1; r v

Fig. 3 is a view of structure, similar to that illustrated in Fig. 1showing the workpiece being vibrated;

1 Fig. 4 is a view of structure, similar to that illustrated in Fig. 3showingthe vibration of the workpiece normal to the direction ofreciprocation between the tool and workpiece, and

bonding materials for abrasive fixture.

- stone s.

. V 3T 7 Fig. 5 is a broken view. of the structure illustrated in Fig.3, showing the addition of a second vibratory ele- .ment thereto. 7

'. In Figs.'l and 2, a honebody lis illustrated inwhich .that the body 1may be rotated and the workpiece supporting table'may be reciprocated,as is also the conventional practice in the arts The drive shaft-3passes through an electromagnetic coil 6 and forms. thecore thereof, Thecoil 6 is housed in a-casing 7 which is secured to the frame 8 of themachineor work-holding The body 1 of the honing tool has a pairofcamming elements 9 and 10 on'a vertically movable adjusting rod llmounted within the drive shaft3. The

bonded abrasive honing stones 2, along with their related cone-engagingelements 12, are mounted inradial slots '13 in-the body 1, with'thesloping surface 14 of the elements 12in engagement with the cones 9 'and10. The, axial movement of the rod 11 and the cones 9 and 10 withrespect to the body lproduces the radial adjustment of the abrasivehoning stones 2. The adjusting rod 11 is engaged by a feed mechanism(not shown) within the head 5 which adjusts the rod axially to-causeradial expansion or'retra'ction of the abrasive honing stones 2.

Due to their magnetic properties, ferrous metals containing more than 6%and less than 79% of nickel elongate and those having 81% or moreofnickel shorten when subjected to a magnetic field. The degree of'thisrespective lengthening and shortening is a function of the fieldstreng'th to which they are subjected and varies for dilferentmaterials. It is therefore preferable; for the potentialofmaximum'amplitude, that the drive shaft '3 and the adjustable rod--11be composed of materials'having these'opposite properties. Thus, when analternating or-pulsing current is impressed through coil 6 of the deviceshown in Figsgl and 2, the resulting lengthening of the adjusting rod 11and the shortening of the drive shaft '3' causes greater relative axialmovement between cones 9 and 19 and the cone-engaging elements 12 witha" consequent radiaLmovement of'the abrasive honing stones with'respectjto the workpiece surface. a I Normal radial expansion or feed pressureof the abrasives is produced by devices such as shown in the United 4through a variable amplifier 16 whose output is conducted to the coil 6through leads 17 and 18, the oscillator being connected to the amplifierthrough a circuit 19 having a switch 20 therein. Y

A workpiece 21 represents a typical part having a large mass and adisproportionately small bore surface 22. The workpiece is mounted on awork-holding fixture 23 on which it is securedagainst rotation in asuitable manner, not herein illustrated. A table 24 supports the fixtureand maybe mounted in fixed position. The head 5 and tool 1 are moved,relative to the table in reciprocation. In the present arrangement, thecasing 7 is retained in fixed relation and thetable 24 is moved upwardlyto have the tool I inserted within the aperture 27 of the Workpiece, andthereafter the tool 1 is moved in reciprocation to stroke the workpiece,In this particular arrangement, the hone body 1 is rotated andreciprocated when the workpiece and body are in the position illustratedin Figs. 1 and 2. Pressure is applied to the upper end of the adjustingrod 111120 have the cones 9 and 10app1y anoutward pressure to'theengagingrelements 12Which force the abrasive stones 2 outwardly againstthe surface of the bore 22 with a predetermined pressure. This willprothe faces of the abrasive stones 2 and the surface 22 which resultsin the minute breaking down of the engaged surfaces of the grains of thestone faces with the surface, to thereby maintain sharp .points on thegrains which produces the continuous rapid cutting without any glazing.In the particular arrangement, a lengthening and shortening of the driveshaft 3 and adjusting element llproduce a minute amount of reaction andadvancement of the cones 9 and 10, which thereby alternately relievesand applies pressure to the stones. This maintains a cuttingrelationship between the grains and surface as glazing is prevented bythe constant breaking down of the grains and the bonding material.

' to the work-holding fixture 26. The wave energy pulse isStates-patents above mentioned. The additional jradial l 'pulsatingmovement resulting from the above described magnetostrictive effectcreates forces at the interface between the abrasive stones and theworkpiece surfaces, not

possible by pressure alone, which dress the abrasive surface. Thus,penetration of the abrasive grain into the material of the workpiecereadily occurs wherever .the former is harder than the latter and thefrequency of impact between them approaches, or is some multiple of, thenatural vibrating frequency of either of them. At the point ofresonance, the interface'between the abrasive stones and the workpiecesurfaces absorbs and dissipates energy at a maximum rate. The period ofresonance of thevtool body, the abrasive stones or the workpiece, or amultiple thereof may be employed so longas thetotal energy (mass Xvelocity) is sutficient to cause the desired disintegrating impact onthe cutting faces of the abrasive The source of current, as shown inFig. 1, may initiate from an adjustable frequency 'oscillator'15 ofeither'the Hartleybr-the balanced reactance type an'd be controlled by amagnetostrictive or a-tuned circuit primary' oscillaseries relation toeach other.

applied directly to the fixture and workpiece which is hereinillustrated as a cylinder'block27. A resonant vibration is producedbetween the surface 28 of a. bore of the engine block and the stones 2of-the hone body 1 by a transducer 29 whichlis supported upon a bed 31of 'the machine and'secured to a corner of the fixture 26. An

oppositecorner of the fixture is secured -tothe bed by suitable'means,herein illustrated as by a shoulder element 32 which is similar to thesupporting-portion 34 of the transducer 29, permitting movement atthecorner. This is desirable so that the element 32 may be'removed and asecond transducer applied to the bed 31 for vibrating a second corner ofthe fixture 26. The'transducer 29 has ahousing 33-, supported in theportion 34 through which an armature 35 extends and connects to a cornerof the fixturel26. The armature is brazed or otherwise secured to alaminated core 36 of sheets of nickelhaving a slot 37 therein providingtwo branches 38 and 39 about which coils 40 and 41 are wound anddisposed in The leads 17 and 18 of the coils 40 and 41 are connected toa variable amplifier 16 which amplifies the signal fromthe oscillator15. A circuit 19 interconnects the oscillator to the amplifier through adisconnecting switch 42. Pulsating current from the amplifier energizesthe coils 40 and 41 and produces a high order of vibration tothearmature 35. This will cause the plate 26 to rapidly move upwardlyand downwardly a minute amount, to thereby superimposea vibrationbetween the surface :28 of the bore of the-block '27 and the faces ofthe stones 22. This causes the breakdown of the engaging points of theabrasive grains to produceuew'and sharp pointsthereon which therebymaintains maximum efliciency in the abrading of the surface 28 of thebore. r

In the present arrangement, a standard 44 extends upwardly from the base31 from which a portion 45 projects frontwardly for supporting the head5 in position to maintain the drive spindle 4 in operating relationthereon. A motor 46 is mounted on top of the standard for drivingmechanism Within a casing 47 which drives the spindle 4 in rotation andreciprocation in a conventional manner. A normal operation in rotationand reciprocation is performed upon the surface 28 of the bore by thehoning body 1. Superimposed upon this normal operation is the vibratorymotion applied to the engine block 27, resulting in a vibrating motionoccurring between the surface 28 and the faces of the stone 2 which, aspointed out hereinabove, produces the continuous sharpening of thestones, resulting in a maximum etficiency in the performance of theabrasive operation.

Fig. 4 illustrates a similar construction to that of Fig. 3, with theexception that a second transducer 48 is applied to another corner ofthe fixture 26, and it is to be understood that a transducer may beemployed at all four corners of the fixture 26 which is desirable whenextremely heavy workpieces are supported thereon. When two or more ofthe transducers are employed, they are actuated 180 out of phase onopposite sides of the fixture. A self-balancing phase inverter 49 may beemployed for this purpose, connected with the amplifier 16 and directlyto the transducer 48 through a circuit 51 and parallel to the circuits17 and 18 through a circuit 52. A pulsating current 180 out of phase isthen supplied alternately to the transducers 29 and 48, therebysuperimposing the desired order of frequency of movement to the fixture26 and engine block 27 which superimpose the vibratory motion betweenthe surfaces of the block bore and the honing stones.

In Fig. 5 a still further form of the invention is illustrated, thatwherein the tool spindle 3 is supported upon the machine spindle 54which is driven in rotation through the gears in the head 55 andreciprocated through the action of the rocker bar 56 driven by thepitman 57 from a motor 58. The workpiece, herein illustrated as acylinder 59, is mounted in a fixture 61 having a supporting leg 62attached to the base 63. A transducer 64, similar to the transducer 29above referred to, is mounted on a vertical wall 65 of the machine, withthe armature 66 disposed horizontally and attached to one side of thefixture 61 at 67. The conductors 17 and 18 from the transducer 64 isconnected to the oscillating and amplifying mechanisms 15 and 16 in thesame manner as illustrated in Fig. 1. Pulsations are produced to thearmature 66 at low magnitude and high frequency, to thereby apply avibration between the surface of the workpiece 59 and the stones 2 in adirection lateral to the direction of reciprocation of the tool. InFigs. 1 and 2, the vibration was produced in the tool itself, and in thestructure illustrated in Figs. 3 and 4 the vibration was applied throughthe fixture, and in all four instances the vibration was parallel to theengaged surfaces of the stones and the wall of the workpiece. In thestructure of Fig. 5 the vibration is produced in the workpiece laterallyof the movement in reciprocation between the surfaces of the stones andthe bore. This movement produces the breaking down of the grains of thehoning stones and the most efficient and rapid abrasive action on thebore surface in time and cost.

With the use of the transducer or transducers, the roughing operation israpidly performed to increase the diameter of the bore to desired sizeand when size is approximately reached the transducers are interrupted,preferably through the operation of the switches 20 and 42, and theoperation of the honing tool is continued for a short time for producinga desired finish on the honed surface. Not only is an extremely accurateand rapid abrasive operation performed on the bore, but without shiftingthe work to a second machine or changing to a tool with finer grainstones, the finishing operation is performed. Through the use of amechanism for superimposing a high order of vibration on the normalabrasive movements employed between the stone faces and bore surface,many benefits are obtained. A more accurate bore diameter is machined ina much shorter time with an increase of stone life. The destructivebreakdown to the stone face, heretofore found necessary after the grainsbecame glazed, is eliminated, making it possible to employ abrasivestones'having much harder bonds. Finally, in performing the finishingoperation without removing the work and transferring it to a secondmachine or changing the stones in the tool, further time and cost aresaved.

What is claimed is:

1. In a honing device, a honing tool having an abrading stone and meanswithin the tool for moving the stone outwardly to increase the tooldiameter, means for operating said tool in rotation, a support for aworkpiece, means for relatively advancing a workpiece and the stone ofthe tool into working relationship to each other, means for relativelyreciprocating said tool and workpiece, and means for producing arelative vibration radially between the workpiece and stone in a highorder of reciprocation for dressing the stone face during the honingoperation.

2. In a honing device, a honing tool having abrading stones and meanswithin the tool for moving the stones outwardly to increase the tooldiameter, means for operating said tool in rotation, a support for aworkpiece, means for relatively advancing a workpiece and the stones ofthe tool into working relationship to each other, means for relativelyreciprocating said tool and workpiece, and an electrically operatedtransducer for producing a high cyclical vibration laterally of saidreciprocation between the stone faces and the wall of the workpiece.

3. In a honing device, a honing tool having abrading stones and meanswithin the tool for moving 'the stones outwardly to increase the tooldiameter, means for operating said tool in rotation, a support for aworkpiece, means for relatively advancing a workpiece and the stones ofthe tool into working relationship to each other, means for relativelyreciprocating said tool and workpiece, and an electrically operatedtransducer for producing a high cyclical vibration laterally of themovement in reciprocation between the stone faces and the wall of theworkpiece, said vibration occurring transversely of the stone faces.

4. In a honing device, a honing tool having an abrading stone and meansfor adjusting the stone radially, a

support for a workpiece, means for relatively advancing the support andtool to have the stone advance into engagement with the surface of theworkpiece to be honed, means for relatively reciprocating the tool andworkpiece and for relatively rotating the same, transducer means onopposite portions of said support, and means for energizing saidtransducer means in one portion out of phase with the other portion.

5. In a honing device, a honing tool having an abrading stone, anadjusting rod within the tool for moving the stone radially, a drivingspindle supporting said tool and through which said rod extends, saidrod and spindle being made from materials having coefiicients ofmagnetic expansion and contraction different from each other, a coilabout said spindle, and pulsating current means for energizing said coilwhich produces a high cycle of relative longitudinal movement betweenthe rod and spindle for changing the pressure exerted between theabrasive stone face and the surface of the workpiece in an extremelyrapid manner.

6. In a honing device, a honing tool having abrasive stones, a spindlefor supporting and driving said tool, an adjusting rod through thecenter of said spindle for applying pressure to the abrasive stones,said rod and spin- '7 d le:being eonstgnc ted of material having'difietent coefiicients ofiexpansion when Isubjectedto a magnetic'field,andmeans for subjecting said spindle and rod -to-a vibra; torymagnetic-'field for producing a high cycle of 'relative longitudinalmovement-betweenlsaid rod and spindle. =7;- In-a honin'g dgevicqa honingtool havingan abradingstonland n i'ean's withinihe tool for moving thestone outwardly to increaseithe tool diameter, means for operating said'tool in "rotation a support for a' workpiece,

means for relatively advancing a workpiece and the stone of the toolinto working relationship -to each other, means for-relativelyreciprocating-said tool and workpiece, and means for producing a highforder ofvibration to the support andworkpiece laterally of the movementin reciprocation between the stone and workpiece ion dressingthe stoneface during the honing operation;

'9 J' 7 5 iieferencesgCi ted in'the'fi1e of-this patent j nmet) STATESPATENTS 7

